Filter bed cleaning



y 1944- J. B, GOLDSBOROUGH ,35

FILTER BED CLEANING Filed Feb. 17, 1940 INVENTOR J. B. GOLDSBOROUGH 2A4ATTORNEY fluid jets. In said. pate'nt tmPruyn; the upper Patented July4, 1944 i John-B. Golds'borough, Crotb'i'i mini-again, assignorj toUnderpinning & Foun n j v Ciorlipanyy 11120 New York; N. Y acorporationApplication February 1'7, 1940; Serialv No 319,40

} '3 Clainis; (01. 210 1281' This invention'relatesto 'filter bedcleaningain part of thecaissonwithout carry ng sand therefiltration ofliquids and more particularlyto-imwith Therevmayb cg i der pleerosion insaid provements in filter bed' cleaning means" adapted downturned upperndsrofvtheiteeth and-inother to travel along th upper faceofadownward flw parts of said teeth, thus causing relatively rapid cel m 1232 erar'rglateflalandtgemove th deteriorationof saidteethandi'tendingtoicause e -W 8 m erla mm 6 graml the cleaner tobeztakeiif-ouifiiofz use finivorder to filter-bed material, from -thebottom to the? '6 P enablerepair. ahd replaem'ent50f=parts The of saidbed, The filter-bed-cleaner of the-pres prior cleaners 1 6i had ntheisadvamageous ent invention is in general an improvement on e u es; v.n11? fig; g 12 fgg p m w An important"object"oftthe presentiinvention qis to provide novel and'ad'vantageous. forms of rf It f t certainfilter-bed cl'ea'ne'rsz' Anotherobj'etofttheinvm $35132?iiiiifufilliifia m iiiafi r as at fac'ekof the 7 a 1 m v t 4 ?fi 3 5? fi 1, In'liquid purification v such as' purification of Chane-'1 why?"qllqwfi'teithatmqugh sewage,"-a 'largetproportion 0f the solids may bewhlchhthev granularmatenaldor Sang) mi F removed -hysettling and th'e'supernatant-liquid h ifl gfi ggfi may then be filte're'd,--for example;by 'passingit through=a filter bedof granular material. The filter bedmay-be in" afiltertank or 'channelwhich is divided by 'a filter 'bedinto an upper portion receiving supernatant liquid from" the settlingtank and a-lower eflluent portion or chamberin 1 z, which collects" theeiiluent or 1iquid"fi1tered"by vepteqfr-omgasstflgggeqgyvtqthe passagethrough the"filter bed; The filtered Egg whgre h n W i liquid or"efiluent is dicharged 'from' the effluent I e chainber i against aheadwhich is 'sufiicient to keep theeflluent'chamberfulli 1% certaincleaners heretofore in' use include for each'-clean'er a caisson orchamber having an .1 t a, V l openrbottohi and engaging: theuppersurface of a a d-. l p u h atre- 1 filter bed so as to segregatethepartof the' filter eed-mile BE QU s bed beneath-the caissonandienable cleaning'of f e the granular material beneaththecaisson.fillld Jets- Across the interior=0f the caisson 'a're arranged aiplurality of hollow" teeth having. their lower ends adjacent thescreensupporting the granular H H filter bed material and their upper endsabove the upper surface of v the filter bed-iinside said caisson. The'sa'nd or other granular 'material may bepassed or pumbewupwardlythrough the v teeth inany 'suitable' manneras by the u'se oi ends'ofsuch hollow teethare turned downwardly to' direct the-flow of sanddownwardly toward the surface of 'the filter bed so that the: sand'di'scharged fromthe'upper ends-of the'teeth will Other; objects;vfeatures.and'wadvantagesawill be deposited on the surfaceoi the filterb'edleavappear upon consideration? of th' zfouowingfda in'gthewastematerialwashed' therefrom;in the ta'i-Ied description"? andaofthe d'rawi-ngziinrwllk h: dirty-'water in said caisson.- 4 Fig: 1isa"fragm htaryiseetional: vleW:'- ;i1 lus- Th'e d-irty waterre'sultmgjfrom -the "-=c1eaning A tratirig -one 'formvof filterliedycleaneitierrriiodyiw e: ifihdrawnfro'ni the upfie'r ing"the"present irlverition, idcdnnectidnnwiththia For convenience the filterbed cleaners present invention will be illustrated I as applied toapparatus of the general type disclosed in the patent to Streander2,086,629, Ju1y'13, 1937. Re-

v ferring to Figs. 1, 2 and 3 of the drawing, afilter bed cleaner l0,embodying one forni- Of the present invention, is illustrated asarranged for cleaning a filter bed II in an endless filter channel-ortank l2-at th'e periphery of: 'a settling tank 13 having a'peri'pheralwall 14:;The filter bed is made 'up of suitable g-ranularmaterial'suchassandy. -i

V In Fig. 1 thefilter: ad theater l2:is illustrated as mounted on said::iwalll4.iand the interior-of the filter bedchannel-isseparated from theinterior:of the-settlingltankjiby the inner-wall l5 of the filterchannel. The supernatant liquid in the settling tank may. be 'admittedinto the 'upperxpart ofthe. filter 'channel .l2 inany suitable manner,:for. example, -through passages. I6.

illustrats -weardly and then curves upwardly, thus serving v to depressthe granular materials and waste These passagesnareuinclined upwardlyfrom: the

interiorof the..sett1ing-.- tank; .to ,theinterior of the filter channelthe liquid levelsinv the two tanks may be maintained so that both endsvof the passages will besubmerged. Obviousl the arrangement-is such as toguardagainstthe pas- -sage .of; scum from the settling tank .to theinzlta hp d he mder top tha I t ter e channel; l2, although illustrated"as mounted, on

- theperipheral wall 'of the'tankQ might also be located eitherinsidethetank or outside the same. It should also un' clerst oodthat the'filterbed cleanerjimay'be 'used tanks or channels differing inf shape from theendless 'channe1 referred. to hereinbefore, for" example i'n arectangulartankL, V T The filterjbed lll restsonfa suitablefsubport n me-I ]la'f.s re e dj v i h ch n into "an uppergporti ohj receiving;supernatant iiquid'f jtne' settling tent s "and a lower orefiluentffchaniberf I8 receiving "the filter liquid pom. the bottom ofthe "filter fb'ed; Said eflluent chambr' is maintained full due" to the'factfthat the downward flow through the filter bed is effected againstan fermen head sufficient to' control the rate of ffi1traticn. fFrom theeflluent "chamber l8, theeflluent "passes" through one or more passages'into tlie' "bottom of an eifluent channel, I9 from whichthe eflluentmaybe discharged over'a'weir'2Q into'another channel 2| from which theremnant is dir e ct'ed through one or more ducts 22' toany'desireddestination. The liquid levels{i'n:the settling tank 10,filter bedchannel I2 andchannel I!) ma be as-indicated at, 24 and-25;=res'pectively, on Fig. l.

The filter bed cleaner l0, which may be-moved along ='the channl l2by'rany suitable means, is 'illustrated-in' Figs. 1

2": and- 3: as comprising a caisson or chamber-26 open'at ltsbottomwhich engages thefilter bed I latits upper surface, and having sidewalls'21 proiectingudownwardly into thegranular material of zthefilter bed toeffect a substantial seal at said side walls. The caisson also comprisesa rear wall 28 which may be provided at its lower part with a sheetmember or flap 29, of any suitable material, riding on the upper surfaceof the filter bed and tending not only to smooth the part of the filterbed just cleaned but also to maintain a seal with the upper surface ofthe filter bed. At its front the caisson may be provided with a'frontwall 30 which at its lower edge is provided with a part or lip 3| ofwhich the lower surface extends forsolids'so that they will pass undersaid front walll' The lip 3| may be integral with said front wall orseparate therefrom and secured thereto in suitable positions, and may beso positioned tha'tliquidand solids may pass thereunder into thecaisson. Preferably the caisson is provided with a top 32 and issubmerged, thus avoiding the building up of a wave at the front of thecaisson.

-As viewed in Fig. 2; the cleaner l0; whilezi'n use, travels to theright. During this movement, some-solid-bearing liquid entersvthe/caisson une der the .frontvwall thereof andpgranular filter-bedmaterial and accumulating contaminating solids are passed upwardly fromthe bottom ofv the filter bed I I through passages 33.:in suitabledevices or hollow teeth 34,:each of; which extends from its: upperfend-Lin the ecaisson downwardly to the lower part of the filterjbedjust above; the screen or filter bed support' l'l. -During;the-.movement of thet cleaner the teeth -34 act to rake 1and;agi-.- tate the?material. of the filter bed. l.l..; & 1.3.";"1':

. The hollow teeth 34 -may,;.a s long as theytake care of a all thematerial throughout the width of the cleaner, be arranged inany-suitable manner. As illustrated, there is arsingle row. of hollowteeth 34 extending .across thecchambervor caisson. However, if the teethwererarranged too close together, "the granular ,material or ,3- sandwould be piled uplbefore the; teethkastheyrad-v vance. 1 Such-piling upmaybe lessenedzor substantially eliminatedyby arranging the teeth ina;plurality ofsuccessivegrows and; if desired -in staggered positioninsaid successive rows.

T The cleaner l0 may besuspended from a bridge 35 pivotally mountedzatthe center of the. tank V 13' -in ;a manner. not shown, and, supportedat.-its

outerend by one or more wheels-36 carriedtheree by and resting on a:rail13'l;.on top; of the outer wall of the filter, bed channel l2. .The:bridge;35 maybe driven .in ;any suitable. manner, for ex? ample .in themanner disclosed. in said. Streander Patentt2,086,629.- -.-,-Thestructure thusfar :described may be.-in

.general similar to the structure heretoforezi'n usezexcept for-the.teeth 34.in which the passages 33are'substantial1y straight whereascorrespond? ing passages in teeth .hBI'BtOfOIQiIlfUSB. such pas:-

sages were not straight and. thelteeth weremape idly destroyed by.abrasion. Althougmthepteeth 34 aregillustrated asbeing substantiallyyertical. it should be understood :that-thein'positions may be varied;The granular. material -m, y;be passed upwardly through. the teeth534;.zby {any suitable means such as upwardly turnedifluidz *jetsnornozzles 38. located in the passages 33; sai;d; teeth ;34,.-prefera ar th.lower:;. n s;. f;said. t e h- .Fluid such as water may be'drawnfromthefilter bed channelplz by a-p ma;dri e sb ra m b whi h, a e s o te by)sa1 -br a and forced through .auct AJIQaz r aniiP 2 an individu n sorduct ta hazllpwer y directed jets 38. The manifoldjj may'be support'ed'from' the' top '32" of v the caisson? and the teeth34"m'aybefsupportedby"the pipes 43? Preferably" the teeth are providedat their lower ends withbaiiles'44' for the same 'general'purpose' asthose disclosed said Pmyn' Patent 2,182,094; that is to control' theflowof granular material tothe lowerendsofithe hollowteethi During" the"upward. flow; through the hollow teeth" 34, of' the granular materialand" collected impurities and" the" discharge of the liquid and solidsfrom the upper" ends 'of' the teeth," the gran ular fmateriafwill bewashed and scoured to ,sep-" arate the impurities from the granularmaterial:

After" leaving the upper ends or the teeth, the

granular material will be" further washed and scouredand' willeventually settle" "on the"- surface of thefil'ter bed, the impuritiesbeing leftin' s'us-- pension in the liquid. The granular material orsandd'is'charg'ed from the'teeth and settling on the bed also serves tostir up the layer of contaminating solids on the upper surface of thefilter bed and to pass them into a state of suspension in the liquid inthe caisson.

The dirty liquid or water'thus produced must be withdrawn from thecaisson and preferably is withdrawn through a suction chamber or box 45at the top and rear of the caisson. Preferably the chamber 45 extendsall of the way across the caisson and the dirty liquid enters thechamber through one or more openings 46 in the front of said chamberjust below the caisson top 32 to aid in preventing the sand or othergranular material from entering said chamber 45. Preferably the suctionbox 45 has a top which covers the box except at one position where itconnects with the lower end of a pump well 41 which extends above theliquid level in the filter channel. Obviously the width of this pumpwell is relatively narrow as compared with the Width of the caisson andresistance to movement of the caisson is greatly decreased. 7

The dirty water may be removed through the pump well 4'! by means of asuction pump 48 supported from the bridge and this pump may be driven bymeans of a motor 49 also supported by the bridge. If desired, the pump48 may be lowered so as to be located in the suction chamber beneath thewell 41. Thedirty liquid from the pump may be discharged through a pipeline 50 to any suitable location.

Due to the fact that the sand or other granular material passes througheach tooth in a substantially straight line and passes therefrom in anupward direction, there is considerable danger that, if no provision bemade to prevent it, sand will pass directly from the tops of the teethdirectly to the suction chamber 45 and into the same notwithstanding thelocation of the openings 46 in the front of the suction chamher. Thisdifficulty may be avoided by deflecting the flow of granular material soas to direct the granular material downwardly and lengthen the path offlow from the upper ends of the teeth to the openings in the suction boxor chamber 45.

Such deflection of the flow from the upper ends of the teeth 34 may, asillustrated in Fig. 2, be effected by a deflector 5! in the form of aninverted trough extending completely across the caisson 32, that is fromone side wall 21 to the other. Said trough is preferably ofabrasionresisting material and may have a cross section in the shape ofan inverted fiat V with the point of the V a little to the rear of thetops of the teeth so that the flow from the tops of the teeth thusturneddownwardly" willact' to sco'ur the top of the-*bed nd remove-tlrierefrom"impurities" which will be placed in suspension in the dirtywat'erer liquid? The -dirty wateit-thusireed from sand,willfflow-throughone o'r moreopenings 46 water isremoved by'the-pum'p48. A I i 'Dil' tdftlie spacing-er; the de'fiect0r 5| frorni the upperends'of the tecth 3 4"; the=streanl ofsahd' and liquid s'p'readsconsid'erably before striking the deflector thusttending to p'revent'excessive abrasion at a limited number of pointson the deflector.Obviously some of the sand fiowi'ng upwardly from the teeth will-strikesand "previously deflectedby-the deflecto'r and tend toproduce aintotlie suction chamber '45; from-which the dirty very effectivecleaning action.

A'ccording to a modificationor second formof the invention, the singlebafile 5| of Figs. 1, 2 and 3 may be omitted and each tooth 34 may beprovidedv with a deflector 52 shown in Figs. 4 and 5. Each deflector 52may be of suitable material, for example metal highly resistant toabrasion, and may have a curved portion adapted to fit over the front ofa tooth 34 at its top. Above the top of the tooth the deflector curvesgradually toward the rear until its is turned downwardly. Also as thedeflector curves to the rear, it spreads gradually until it becomessubstantially straight in a transverse direction. The deflectors 52 mayeasily be replaced.

A further modification or third form of the invention is illustrated inFig. 6 and comprises a battle or deflector 53 which is downwardly andrearwardly inclined at the rear of the teeth 34. As shown in Fig. 6, thestreamof sand from the teeth does not strike the bafile or deflectordirectly but the dirty water inthe caisson'is compelled to flowdownwardly around the lower edge of the deflector before passing to thepump cham: ber 45, thus effecting separation of the sand and depositthereof on the top of the filter bed, 0bviously the deflector might beso shaped and positioned as to be struck directly by the sand flowingfrom the upper ends of the teeth.

It will be evident that, due to the substantially straight passagesthrough the teeth, the abrasion at the interior of the teeth will beminimized, thus enabling the teeth to be used for a long period beforereplacement; The deflectors are of simple form .and can be replaced moreeasily than the teeth.

It should be understoodthat various features may be changed and thatcertain features may be used without others, without departing from thetrue spirit and scope of the invention.

What I claim is:

1. In a cleaner adapted to travel over a granular filter bed, thecombination with a caisson having an open bottom substantially inengagement with the upper surface of said bed and means for dischargingdirty liquid' from the caisson, of a plurality of hollow teeth extendingfrom the interior of the caisson downwardly to the lower part of saidfilter bed, each of said teeth having a substantially straight passagetherethrough with an inlet at the lower end and an outlet at the upperend of said passage, and deflecting means to direct granular materialflowing from the upper ends of said passages downwardly to settle onsaid filter bed, said deflecting means comprising an inverted troughextending substantially from side to side of the caisson.

2. In a cleaner adapted to travel over a gramular:fi1te1t bed..: the vcombin ti n wit a. .c havin an ppen ebq om; t bs a n ia y n nga ementMwih-tt e; u en ,sur eqe-pi w l bed. and eans for dis ha in irt i ui r m,the caisson, of a, plurality of hollqw-teeth extendin from the interiorof the caisson 'clqwnwardly to t we p o sa dflfilt r be -.ees=h1 w leth. hav t bsta tie yztstra h a s therethrough with, an inlet at thelower end and anoutlet at the upper end pt ,said passage, and deflefllinmeans 4 t9 dire qt granular naterial flowing f om ,the'kup per ends pf,said passages downwan wtmse e 0 .sa te bedifia d d flegting meanscomprising an inverted t1"ough xt n in s stan i y qmz i t si of theqaisspn er d so positioned; as todeflect the granular materialrearwardly as well as downwardly. v u V 3 In a cleaner adapted tpttavelOver a. granular filter bed, thercoinbination with a caisso n hevimg ar'dfieji bpttbih substantially i i engage-Q meritiwith thefupper fsurfacefof slaid bed and meji s'fr 'discharging dirty liquid from the c ai's-rsonfof ablurelity of. hollow teeth'exteiidi n'g'f'rom theinteiiof fthe"c'aLis'sofi ddwriwardly to the lowef part (if "said filter bed, each of'said teeth having a siib'ste'ntiallystraight passage thereth rbugh'with a'r i', inlet' at the lower end and an outlet at thejupper'endbfjsaid passage, and defledtifig nja'riitd dirept' g'fam laz materialflowin'g fz c x'fi"tlieliipprlends 6f aidpas'sa'ge's 'dpwr wardljyto'sttl or; Sid'fil'ter bed, 'Saiddefie'ctihg' means cbmpi'ising' alninverted trough extending substeintially frdm. side to side Of thejeaisson' and hajin' t its interior two plane surfaces, meeting in a'liri'e extending longitudinally 'of the trough.

' "JOHN O DSBOROUGH;

